北京斯芬克艺术留学托福听力海洋生物学背景知识:珊瑚白化

时间:2019-12-12 15:14:06 托福听力 我要留学

托福听力词汇以及相关背景知识的积累专业艺术留学网址,是一个相当漫长的过程,需要考生在平时的生活中多总结专业艺术留学网址,多记忆。艺术留学的老师为大家整理了托福听力海洋生物学背景知识:珊瑚白化专业艺术留学网址,希望对各位同学的托福听力备考有所帮助:接下来为大家介绍"专业艺术留学网址详述托福听力海洋生物学背景知识:珊瑚白化"
托福听力海洋生物学背景知识:珊瑚白化

Introduction:

Coral Bleaching

珊瑚白化(coral bleaching)就是珊瑚颜色变白的现象。珊瑚本身是白色的,它的美丽颜色来自于体内的共生海藻,珊瑚依赖体内的微型共生海藻生存,海藻通过光合作用向珊瑚提供能量。如果共生藻离开或死亡,珊瑚就会变白,最终因失去营养供应而死。由于海洋温度不断升高,致使珊瑚所依赖的海藻减少,珊瑚也因此更易受到白化的影响。三十年前,大规模的珊瑚白化现象比较罕见,但近年来却越来越多的出现。

Background information:

Coral bleaching is the loss ofintracellular endosymbionts through either expulsion or loss of algalpigmentation. The corals that form the structure of the great reef ecosystemsof tropical seas depend upon a symbiotic relationship with algae-likeunicellular flagellate protozoa that are photosynthetic and live within theirtissues.

Monitoring reef sea surface temperature

The US National Oceanic and AtmosphericAdministration (NOAA) monitors for bleaching "hot spots", areas wheresea surface temperature rises 1 °C or more above the long-term monthly average.This system detected the worldwide 1998 bleaching event, that corresponded toan El Niño. NOAA also uses a nighttime-only satellite; these observations aretaken at night to avoid the increase in temperature due to daily warming causedby solar heating at the sea surface during the day. This is also a precautionto avoid glare from the sun.

Changes in ocean chemistry

Increasing ocean acidification due to risesin carbon dioxide levels exacerbates the bleaching effects of thermal stress.Acidification affects the corals' ability to create calcareous skeletons, essentialto their survival. A recent study from the Atkinson Center for a SustainableFuture found that with the combination of acidification and temperature rises,the levels of CO2 could become too high for coral to survive in as little as 50years.

Knowledge points:

1. 珊瑚白化是由细胞内共生菌的丢失引起的。

2. 监测海洋表面温度,是预防和分析珊瑚白化的方法之一。

3. 二氧化碳的上升引起海洋酸化的加剧,恶化了漂白作用。酸化作用影响珊瑚石灰质骨骼的创造能力,而这对他们的生存至关重要。

Vocabulary prediction:

Coral    珊瑚

Bleach    变白

Resilience    回弹,弹力

Smother    窒息

Test Point – TPO27L1

Now, we’ve talked in depth about coralbleaching, or whitening, which as you recall, is a symptom of ...well that thecoral is suffering. As you know, coral is very sensitive to water temperature.Even though one or two degree Celsius rise in sea surface temperature for arelatively short amount of time can cause bleaching. Recently, researchers haveused data collected by monitoring surface water temperatures to improve theability of a reef to recover from bleaching. One future possibility is thatimproved monitoring can help predict where and when bleaching will occur, whichmight potentially enable us to mitigate its effects.

And there’s another technique that’s beenexperimented with to try to help coral reefs recover from bleaching. It’scalled coral transplantation. This involves moving young coral from a healthyreef onto a degraded reef, you know, in an attempt to regenerate the degradedreef by encouraging young healthy coral to take over. There has been some successwith this, but it’s still somewhat controversial. Some scientists support itbecause, well for one thing, it means you don’t have to rely on the existingcoral to reestablish itself because it might not be able to. But in my opinion,transplanting coral should only be used as ... well as a last resort. I mean,this method is not only costly but it’s ... well even if it’s successful, itstill fails to address the ongoing problem, the root causes of the degradation,which really is paramount to devising an effective solution. So I don’t reallytake comfort in the successes they have had with transplantation.

Knowledge points

1.珊瑚对水温很敏感,即使海面温度只在短时间内上升一,二摄氏度,也会引起珊瑚白化。

2.另外一个解决珊瑚白化的方法是珊瑚移植,是指从健康的暗礁上移植小珊瑚到被损坏的珊瑚上,目的是让小的健康的珊瑚挽回损坏的暗礁。

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